In construction or renovation, underpinning is the process of strengthening the foundation of an existing building or other structure. Underpinning may be necessary for a variety of reasons: … It is more economical, due to land price or otherwise, to work on the present structure’s foundation than to build a new one.

What are the reasons for underpinning?

To increase the capability of existing foundations e.g. to support another storey to the building. Natural disasters such as earthquakes, floods or droughts that have caused the structure to move or become unstable.

Is underpinning a problem?

Although underpinning is often an unwanted expense, if left unresolved the cost could be much higher, putting your entire property at risk. For the sake of making your property structurally secure and safe to live in, the cost of underpinning is often worth it in the long run.

Can you sell a house that needs underpinning?

As we have previously touched upon, you can absolutely sell a house that has been underpinned. When you sell, you will need to declare that your property has been underpinned. Failure to do so can result in legal complications as the buyer will be protected by The Misinterpretation Act 1967.

Can underpinning fail?

If the underpinning isn’t installed correctly, it will be less effective, or even fail altogether. In these circumstances, it may not be sufficient to protect against a return of the subsidence, heave or whatever the original problem may have been.

Can you tell if a house has been underpinned?

The short answer is, is that it can be very difficult to tell if a property has been underpinned from a visual inspection, as the underpinning is concealed below ground and therefore can’t always be seen during the course of a typical survey inspection.

Is underpinning permanent?

Is Underpinning a permanent solution? While nothing is absolutely permanent, underpinning is a solution that should last. It is also a solution that can help with foundation settlement. Underpinning with piers allows us to lift and level the foundation as well.

Will subsidence devalue my house?

How much subsidence devalues a property will depend on how severe and recent the problem is, but a property that has previously been underpinned to address an issue with subsidence is estimated to be worth around 20 percent less than a similar property without any history of subsidence.

Does underpinning solve subsidence?

Underpinning can be used to repair subsidence or to pro-actively increase the structural integrity of a building. This is particularly useful if you are adding an extension or if your neighbours are having issues with subsidence.

How many years do you have to declare subsidence?

Unfortunately, there is no limit on how long you have to declare subsidence. If your property has been affected by subsidence at any point in the past, particularly if an insurance claim on that basis has been made about it, then you do have to declare it to the estate agent and the buyer.

Article first time published on

Why is underpinning bad?

Underpinned properties are considered riskier because it indicates that the property may be structurally unsound, or have imperfect sub-optimal foundations. While in theory the property should be more secure than before, there are no guarantees that it won’t require further structural work.

How much does it cost to underpin a home?

Underpinning just one corner of a house can run $3,500-$5,000 and up. All needed repairs for a typical house with moderate foundation damage start around $8,000-$12,000 but can go as high as $20,000-$30,000. Many homeowners insurance policies do not cover foundation repairs, but financing is often available.

How long does an underpinning guarantee last?

U&M provides a ten-year guarantee of its underpinning solutions for defects, but is that as long as you can expect the underpinning to last? And can it fail sooner? The two main reasons for underpinning to fail are poor installation and new issues arising.

How long does it take to underpin?

Most underpinning jobs are usually completed within two to four weeks, but that doesn’t include all the finishing work required or the walk-out if selected.

How do you underpin a footing?

The most used method of underpinning is mass pour method. This process requires excavating sections in sequence to a pre-established depth below the footing and place concrete on each pit. Repeat the method until the entire affected area has been underpinned.

How do you stop underpinning?

Another approach to avoid underpinning is to use excavation support systems to retain soil below an adjacent building. This will often result in a small basement set-back because the excavation has to be installed near along the property line and takes up space.

Do insurance companies cover underpinning?

Can I claim the cost of underpinning on my home insurance? Subsidence damage is usually covered by buildings insurance, so you should be able to claim back the cost if your house needs underpinning.

Do you have to declare underpinning?

Underpinning must be declared by the vendor or estate agent. If you’re buying a property and you have been misled about any historical work which has been done to the property then you may be able to take the vendor to court, as buyers are protected by ‘The Misrepresentation Act 1967’.

Can I get a mortgage on a house with structural movement?

Most mainstream lenders will accept properties that have had subsidence that has been properly resolved, particularly if no further movement has been seen for 10+ years, so in this situation, you shouldn’t have to seek out special mortgage lenders for subsidence property.

What are the first signs of subsidence?

• Cracks in the walls, ceilings and outside brickwork.
• Expanding of existing cracks.
• Cracks appearing after a long phase of dry weather.
• Rippling of wallpaper that isn’t caused by damp.
• Sticking of doors and windows suggesting doorframes or windowframes have changed shape.

What does a subsidence crack look like?

If a crack is caused by subsidence, it will be: Thicker than a 10p coin (more than 3mm) Diagonal, and wider at the top than the bottom. Visible internally and externally.

What is the average cost of underpinning?

Typically an underpinning job of this scale would cost around $30,000 including engineering and any other miscellaneous costs. We can provide this cost estimate with confidence, as we were given full access to the engineering reports, soil test and site information by the home owner.

How do surveyors check for subsidence?

1. Large cracks (larger than 3mm) suddenly appearing in a wall, usually around a door or window frame, which are wider at the top than they are at the bottom.
2. Doors and windows sticking.
3. If you have an extension, look for cracks where the extension meets the main part of the house.

How much does it cost to fix subsidence UK?

The process can be lengthy and expensive, costing anywhere between £5,000 and £50,000 depending on the size of the property and the extent of the damage. Though figures differ, it is estimated that as few as only 10% of properties suffering from subsidence will require underpinning.

What to do if you think you have subsidence?

If you think you may have subsidence, the first step is to contact your buildings insurer. The sooner it is picked up the easier it will be to deal with. The insurance company will arrange for a surveyor to inspect your home and confirm if it is subsidence.

Can subsidence be permanently fixed?

The only permanent way to deal with subsidence is to give a house the foundations it needs to cope with the ground it is sitting on. ‘You can mend the cracks caused by subsidence but, three or four years later, there will be a hot summer and they will open up again.

Can I getting insurance after subsidence claim?

Homeowners who have claimed for subsidence on their insurance are stuck paying expensive premiums to existing providers because no other insurers will offer them cover.

How common is subsidence?

Subsidence is a common problem for home owners in London due to its construction on London clay; one in 50 houses in London and the South East has suffered from subsidence.

What is bench footing?

Basement benching (aka bench-footing) is another way to add height to your basement. Instead of excavating under the existing basement foundation, a bench or ledge is built around the inside perimeter of the existing walls. Then, we lower the basement foundation within the benched space.

How much is underpinning South Africa?

Starting from R 7 500.00 to R 12 000.00 These rates are dependent on the difficulty of the build and the amount of concrete work required to complete your build. Also, single storey vs Double/Triply storey builds are more expensive and will cost more per m2.

Can a house settle after 20 years?

Every house will see some settlement over the years. In fact, a few inches of settlement is nothing to worry about (assuming this settlement is evenly distributed across the structure). Soil expansion and contraction cannot be controlled and quality construction will hold up under normal variances.